Hard sediment gun corer



Nov. 11, 1969 Filed Nov. 21. 1967 1;, P. FARRELL ET HA RD SEDIMENT GUN CORER 3 Sheets-Sheet 1 Thomas P. Ferrell Jason H. Taylor MENTOR-3 Nov. 11, 1969 1 P. FARRELL ETAAL 3,477,525

HARD SEDIMENT GUN CORER Filed N v- 1- 196'? s Sheets-Sheet 2 Lg Y NW. 11, 1969 -1 p, FARRELL ET AL 3,477,525

HARD SEDIMEN'I' GUN comm 3 Sheets-Sheet 5 Filed Nov. 21. 1967 Fig. 3

United States 3,477,525 HARD SEDIMENT GUN CORER Thomas P. Farrell, Yonkers, and Jason H. Taylor, Stony Point, N.Y., assignors, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed Nov. 21, 1967, Ser. No. 684,847 Int. Cl. E21b 49/02, 7/12; E21c 19/00 US. Cl. 175-4 4 Claims ABSTRACT OF THE DISCLOSURE The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention is directed to gun corers and more particularly to a gun corer from which a projectile carrying a core liner is launched at a point a selected distance above the bottom so as to most effectively penetrate both hard sediment and rock bottoms.

The majority of corers in use today obtain cores by means of either free fall forces or piston coring rigs, deriving their driving power respectively from heavy weights or pyrotechnic sources and entailing the use of special winches and undesirable heavy cable. The free fall corer has not proved satisfactory for many applications because of both its inaccuracy in free fall due to ocean currents, layer densities, etc. and the limited penetrating force which may be obtained from the masses of material which may be conveniently handled by ship personnel. 7

Although piston coring rigs provide a greater driving force than that available in gravity coring, this force has not been derived or developed to the desired point. For some ocean bottom areas such as the continental shelves, none of the existing piston coring rigs have been able to successfully penetrate the hard sand and sand-clay sediments.

A third type of corer, that which is supported by legs on the bottom and derives its driving force from a pneumatic source on board ship, is also unsatisfactory both as to the magnitude of the force available and the great difliculty in positioning the corer at a desired location in a desired attitude. Pneumatic corers are additionally undesirable in handling and lowering them as well as in maintaining their lines free from fouling and escape of compressed gas.

Further difiiculties with existing coring devices include limitations in depths at which they may be used and in locations where they may be implanted. With regard to vibratory driving rigs, e.g. electric, pneumatic or hydraulic, these require a stable base of operation such as a ship anchored with one, two or more anchors. Existing gun corers have been found deficient in adequate safety devices as well as presenting undue difficulty in being pulled out of the bottom.

The present gun corer avoids the disadvantages of prior corers, either pneumatic, electric, pyrotechnic or hydrauatent O 3,477,525 Patented Nov. 11, 1969 "ice lic, by providing for the firing of a 40 mm. shell charge in a gun barrel of a relatively compact and lightweight unit which is lowered by a single cable from a conventional shipboard winch. The firing mechanism is actuated when the descent of a plummet weight which precedes the cutting head of the core barrel is arrested, releasing a spring-loaded firing pin. A manual safety device prevents arming of the device prior to and during launching while a hydraulic safety device prevents firing until the unit has descended to a predetermined depth.

Accordingly, it is an object of the present invention to provide a compact corer which may be substantially precisely positioned above a selected .area of ocean bottom before firing.

Another object of this invention is to provide a gun corer, the firing of which is actuated by means carried by the gun corer device and preceding the corer cutting head to the bottom.

A further object of this invention is to provide a gun corer adapted to drive a core liner into hard sediment as well as into rock and coral.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description thereof when considered in conjunction with the accompanying drawings in which like numerals represent like parts throughout and wherein:

FIG. 1 is a view in elevation partly cut away of the apparatus of the present invention after actuation thereof;

FIG. 2 is an enlarged view of the firing mechanism and breech assembly of the embodiment of FIG. 1; and

FIG. 3 is an enlarged isometric View of the core barrel coupler of the embodiment of FIG. 1.

Referring to FIG. 1, a gun corer 11 is shown in its entirety including a gun portion 12, a corer 13 and a coupler 14 for coupling the gun and the corer. The entire assembly is raised and lowered by a cable or line, not shown, which is attached to an eyebolt 15 on gun 12. Gun 12 preferably includes a reaction plate 16 to which are secured a breech 17, a breechblock 18 and a breech block adapter 19. These components of the reaction plate provide, when coupled with the fluid medium, a sufficient means for absorbing reaction energy. Secured to the under surface of reaction plate 16 by a collar 20 is a gun barrel 21 having a chamber 22 for receiving the projectile to be fired. Breech 17 and breechblock 18 are adapted to receive a firing mechanism 23, the mechanism in this embodiment firing a shell charge 24 such as contained in a 40 mm. shell. Gun barrel 21 is provided at its lower extremities with a flange 25 for permitting severable connection to coupler 14 by means of at least a pair of shear screws 26.

Coupler 14 and corer 13 form a projectile, the coupler including a piston 30 for insertion into chamber 22 and a main body portion 31 having a flange 32 which when the unit is assembled before firing is in register with and secured to flange 25 by shear screws 26. Coupler 14 also includes a lower portion 34 which is secured to main body 31, the lower portion 34 having at least a pair of upper brackets 35 for accommodating retrieving means such as nylon lines 36 which are connected to gun 12 and at least a pair of lower brackets 37 to accommodate attaching means such as bolts 38 for coupling to the corer 13.

Corer 13 includes core barrel 41 having brackets 39 attached thereto to receive bolts 38. Coupler 14 and corer 13 are secured together by means of bolts 38 and nuts 40. Corer 13 is adapted to receive a core liner 43 having a piston valve 44 movably positioned therein.

Core barrel 41 is open-ended and terminates at its lower end in a cutting head 45. Retrieving lines 36 are connected at one end to coupler 14- and at the other end to eyebolts 48 on reaction plate 16. Lines 36 are of sufiicient length to accommodate the expected distance of recoil of gun 12. Gun 12 is further provided with means for actuating firing mechanism 23 before gun corer 11 reaches the bottom such as a plummet 53 which is suspended by a plummet line 54 connected to the firing mechanism 23. A short piece of light twine 55 in line 54 prevents damage to firing mechanism 23 from recoil action.

In FIG. 2 the gun and firing mechanism are seen in enlarged detail, plummet line 54 being shown connected to a transversely movable spring-loaded carriage 56 which comprises two end members 57 and 58 joined together by two connecting rods 59 and 60. The connecting rods are slidably accommodated in a bracket 61 which is secured to breechblock 18. A seer 62, secured between rods 59 and 60 by a pin 63, is spring-loaded in carriage 56 by a spring 64. Seer 62 is received in a transverse opening 66 in an adapter 67 which also has a longitudinal opening 68 through which a firing pin assembly 6% extends. Firing pin assembly 69 is provided with a slot, not shown, into which seer 62 may be inserted, and also is provided with a pair of spaced collars 72 and 73 between which a pin 74 of a hydrostatic safety 75 may be inserted. Bracket 61 and rod 59 are provided with openings, not shown, to receive a pin 80 at the end of a manual safety 81 so that carriage 56 may be locked in the extreme right position, preventing downward movement of firing pin 69.

In FIG. 3 the main portion 31 of coupler 14 is shown, portion 31 being provided with a plurality of symmetrically spaced water diverting slots 85 which terminate along a probe 86 within the main portion 31. Probe 86 serves to intercept and divert water displaced by the entry of sediment in the lower end of core liner 43.

In operation, after corer 13 with a replacement core liner has been secured to coupler 14 by coupling nuts 38, the coupler is secured to gun barrel 30 by shear screws 26. At this point gun 12 is ready for loading and a 40 mm. shell is inserted into breech 17. The breechblock adapter 14, breechblock 18 and firing mechanism 23 are positioned and locked, the firing pin 69 having been cocked and manual safety 81 and hydrostatic safety 75 having been previously engaged. The plummet line 54 with a new piece of light twine 55 is then prepared placing the gun corer in readiness for lowering. The gun corer is lowered by a cable or line, not shown, attached to eyebolt 15 and when the top of the gun corer is about six feet below the surface of the water the manual safety 81 is pulled. At substantially 30 feet, the hydrostatic safety 75 is programmed to release, leaving the unit fully armed for the remainder of its descent.

Upon reaching the bottom, the plummet 53 lands first leading the cutting head 45 of core barrel 41 by a selected amount preferably substantially nine inches. Seer 62 then is released due to removal of tension on spring 64, permitting the firing pin assembly 69' to drive the firing pin into the percussion primer of the 40 mm. shell. The percussion primer then starts the powder train, biulcling up pressure to first sever shear screws 26 and then accelerate the projectile, i.e. the coupler and corer, through the water. As the projectile is accelerated the loose nylon retrieving lines 36 are dragged after it, sufiicient slack having been assured by folds formed therein to preclude tension in the lines. Recoil is absorbed in the water above the reaction plate 17, such recoil snapping the light twine 55 in plummet line 54 preventing damage to the seer and firing mechanism. The water column above piston valve 44 is exited through slots 85 in the upper portion of coupler 14 with a minimum of back resistance. Piston valve 44 together with core liner 43 prevent loss of the core during retrieval of the gun corer. The device is easily retrieved by means of cable 73 which is attached by a frame to reaction plate 16. t

It will be appreciated that the present invention thus provides a compact corer that is adapted to fire a projectile containing a core sample retrieving liner from a position which is a selected short distance from the ocean bottom. The core barrel is positioned in the lower portion of the projectile, and the projectile is fired from a gun which is adaptedto use conventional "shells having smokeless powder as the propellant. The use of such shells avoids the necessity for chambers into which solid propellant otherwise would be required to be inserted and permits rapid reloading thereby increasing the frequency of use of the device. i i v p The entire assembly may be lowered, by cable from a conventional shipboard winch since its Weight is'notunduly great as it would be if a largernass were employed for absorbing recoil. The firingmechanism of the device is provided with two safety features, one being the manual safety which maintains a seer in position in the firing pin assembly at all times prior to the lowering of the device into the water. Upon; removal of the manual safety, a spring-loaded carriage still maintains the' seer in position in the firing pin assembly while a hydrostatic safety further maintains the firing pin assembly from being actuated until the device has been lowered to a predetermined depth. The spring-loaded firing'pin is released as'the plummet weight touches the bottom, the seer being extracted from the firing pin assembly upon removalof tension in the line suspending the plummet weight.

.When a core sample is being forced into the core liner, water above the piston valve is removed with a minimum of back pressure by the diverting probe and associated exit passages. The nylon retrievinglines connecting the gun portion and the coupler are adapted to be loosened at the occurrence of recoil so that no recoil force is transmitted to the coupler and, therefore, to the corer. That is, these lines are provided with sufiicient slack so that the recoil forces are not communicated'to the corer. On retrieval, these lines remove the corer and sample from the bottom, carrying them with the gun portion to the ship where the device is easily hauled abroad. The various features thus provide for the taking of a great number of samples in a minimum of time at a maximum of safety.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings.

What is claimed is: I 1. A compact gun corer adapted for firing a projectile containing a core sample retrieving liner into hard sediment from a position a selected short distance above the ocean bottom comprising:

a projectile and means for impellingsaid projectile toward the ocean bottom,

said impelling means including breech and breechblock means for housing a shell containing an explosive charge; f F said impelling means further including reaction means for dispersing recoil forces in theenvironment and chamber means for receiving saidprojectile; i

said projectile means including liner means "for containing'a' sediment sample and exiting means for diverting water displaced by said sample into the environment; I firing means connected to said reaction means for initiating explosion of said shell charge; means connected to said impelling means for actuating said firing means upon the projectile means approaching to within a selected distance of the bottom, I

said actuating means including manual safety means for preventing firing of said shell charge before lowering of said gun corer and hydrostatic safety means for preventing arming of said firing means until said gun corer has reached'a predetermined depth; v said actuating means further including means intercepting the bottom in advance of the projectile means, '4

said intercepting means maintaining said firing means inoperative until the intercepting means reaches the bottom;

said intercepting means being a plummet suspended by a plummet line from said impelling means; and said actuating means further including a seer which is interposed in the firing means preventing operation thereof until the plummet lands on the bottom.

2. The device as defined in claim 1 wherein said exiting means includes a downwardly extending probe centrally disposed in said projectile means; and

passage means in said projectile means disposed above and communicating with said probe for diverting displaced water into the environment,

said passage means including a plurality of outwardly turned slots for reducing back resistance to a minimum. a

3. The device as defined in claim 2 and further including retrieving lines connecting said impelling means and said projectile means for recovering the projectile and core sample when the impelling means is recovered;

said retrieving lines being provided with sufficient slack to accommodate the relative movement of the impelling means and the projectile means upon firing of said projectile;

said plummet line including means for providing slack line.

References Cited UNITED STATES PATENTS 1,309,708 7/1919 Velo 102--7.4 2,374,261 4/1945 Ames 1029 3,276,368 10/1966 Tower et a1. 1027 3,313,357 4/ 1967 Venghiattis -4 3,345,879 10/1967 Nasu et a1. 175-6 X SAMUEL W. ENGLE, Primary Examiner US. Cl. X.R. 

